Dehydrated particulate food product and preparation thereof

ABSTRACT

A dehydrated particulate food product is made by preparing an aqueous mixture containing albumen and a food acid and combining and mixing the aqueous mixture with a fat in amounts sufficient to obtain an emulsion containing albumen and fat in a ratio of between 0.14:1 and 1.5:1 and having a pH below 5. The emulsion is homogenized and then dehydrated.

BACKGROUND OF THE INVENTION

A normal process for preparing mayonnaise consists of producing amixture comprising egg yolks, mustard, vinegar, salt and pepper, andthen adding oil thereto. In such mayonnaise, the oil-in-water emulsionformed is stabilised by the lecithin contained in the egg yolk, throughits surface-active properties. The mayonnaise thus obtained neverthelesscontains a significant quantity of fat and a high cholesterol content,due principally to the egg yolks and secondarily to the oil used.

U.S. Pat. 5,082,674 proposed a process for preparing, inter alia,dehydrated mayonnaise capable of being reconstituted rapidly through theaddition of water. This process consists of preparing a mixturecomprising a lyso-phospho-lipoprotein (LPLP), modified egg yolks andmaltodextrin, and then adding a sunflower oil so as to form an emulsioncapable of being homogenised and dehydrated by atomization.

Rehydration is effected by the addition of water and enables a productwith a texture and taste comparable to those of conventional mayonnaiseto be obtained. However, this mayonnaise has the drawback of containingegg yolks, constituents that consumers would like to avoid eating fordietary reasons.

U.S. Pat. No. 3,582,363 concerns a dry composition which can berehydrated in order to give a salad dressing. This composition consistsof a dry mixing of the different ingredients. The drawback of this drycomposition is that it may be inhomogeneous and that when rehydrated anunstable product is obtained.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the above-noteddrawbacks and it provide a product of the dehydrated oil-in-wateremulsion type, able to give a mayonnaise after the addition of water,the product containing no egg yolk, therefore being low in cholesterol,nor containing maltodextrin or thickening agents or added stabilisers,while offering a remarkable degree of stability.

Accordingly, the present invention provides a particulate dehydratedfood product, comprising albumen, a source of food acid, a source of fatand optionally seasonings, the whole having been emulsified, homogenisedand then dehydrated, each constituent particle of the said powder havingthe same composition as the whole, the said food product being able toform, after rehydration, a stable oil-in-water emulsion, with a pH below5 and an albumen/fat ratio of between 0.14 and 1.5.

Each particle of the dehydrated product of the present invention has anaverage size of between 50 and 150 microns. The product, in the form ofa powder, is used either as a base for mayonnaise, in which case it hasa lipid content of between 65 and 85%, or as a salad dressing, in whichcase it has a lipid content of between 30 and 65%. This product may havea protein content of between 5 and 30%, a carbohydrate content ofbetween 1 and 30%, and a proportion of mineral salts or other secondaryingredients of between 0 and 5%.

A salad dressing is reconstituted with one part of powder to one part ofwater and a mayonnaise with one part of water to four parts of powder.

Each constituent particle has the above composition of lipids,carbohydrate, proteins and mineral salts.

The present invention provides a process for preparing the product, inwhich an aqueous mixture comprising a source of albumen and a source offood acid is prepared, and combined and mixed with a fat, with theoption of adding seasonings to the aqueous and/or fatty phase. Theaqueous mixture and fat are combined in amounts sufficient so as to forman emulsion having a pH below 5 and an albumen/fat ratio of between 0.14and 1.5. The emulsion is homogenised and the homogenised emulsionobtained is dehydrated.

It was found, surprisingly, that it was possible in accordance with thepresent invention to obtain a dehydrated oil-in-water emulsion having anacidic pH and able to remain stable following rehydration, without theneed to employ stabilising agents such as those in egg yolk, orthickeners such as gums or starches, or emulsifiers such as lecithins.

The present invention is noteworthy for the fact that it makes itpossible to obtain, following reconstitution, a product of themayonnaise type having a reduced cholesterol content, generally lessthan 10 mg per 100 g of dry product. The present invention isparticularly notable in that it enables the use of egg yolk, a verysignificant source of cholesterol, whose damaging effects on health arewell-known, to be completely avoided.

Another advantage of the invention is that it allows easy industrialpreparation of a product that will keep for a long time in powder form.

Another advantage is that it enables a product that is quickly andeasily reconstituted cold, in particular using tap water, to beobtained.

DETAILED DESCRIPTION OF THE INVENTION

In the rest of the present description, the percentages and amounts aregiven in terms of weight.

Thus, in order to implement the process, an aqueous phase is first ofall prepared comprising a source of albumen and a source of food acid.

The source of albumen comes principally from egg white, which may easilybe obtained commercially either in liquid form, possibly concentratedand preferably pasteurised, or in the form of dehydrated powder.

It is also possible to use a mixture of liquid egg white, concentratedor otherwise, and powdered egg white.

It is also possible to add milk proteins such as skimmed milk in liquidand/or powder form, or a concentrate of whey proteins, for example indehydrated form, or vegetable proteins, so as to increase the dry mattercontent of the emulsion obtained, which has the effect of increasing theviscosity of the emulsion and assisting the atomization and dryingstage, while enhancing the texture of the final product. It is possibleto add up to 1 part of skimmed milk or concentrated whey protein drymatter per part of albumen dry matter.

The source of food acid may be citric acid and/or acetic acid, coming,for example, from lemon juice or vinegar.

It is also possible to add to the said aqueous phase food seasonings, inliquid, paste or powder form, such as mustard, salt, pepper, spices, eggflavour, or any other flavouring desired by the consumer such as, forexample, flavours or juices or extracts of fruits and/or vegetables.

It was found, surprisingly, that the addition of seasonings does notbring about a destabilisation of the emulsion, in the form of a phaseseparation, which offers the advantage of being able to seasonbeforehand the emulsion to be dehydrated, so as to obtain areconstituted product that can be seasoned according to the taste ofconsumers.

It is also possible to enrich the aqueous phase with water-solublevitamins and/or mineral salts.

This mixture may be prepared at any temperature, the dissolving of anypowdered skimmed milk in the liquid egg white taking place fasterbetween 30° and 40° C. It is also possible to prepare this mixture at alower temperature, around 4° to 10° C., so as to maintain goodconditions of bacteriological safety.

An aqueous phase is thus obtained, to which it is not necessary to addwater, with a dry matter content of around 20 to 50%.

At the same time, a fatty phase is prepared, which may comprise one ormore fats of animal or vegetable origin, such as sunflower, soya, olive,peanut, rapeseed, canola and/or corn oil, and may also containliposoluble vitamins or any other liposoluble ingredient such asflavourings, aromatic oils and/or food colourings and/or naturalantioxidants.

The fatty phase is added to the aqueous phase in such quantities as togive an albumen/fat ratio of between 0.14 and 1.5.

It has been found that when this ratio is less than 0.14, the emulsionobtained is not sufficiently stable, and that when this ratio is greaterthan 1.5, on the one hand the emulsion contains too much dry matter andbecomes difficult to pump, and, on the other hand, the final productafter reconstitution has an impaired taste and appearance, as well as agrainy, chalky or floury texture in the mouth, probably due to thepresence of too high a quantity of proteins.

Thus the ratio as specified in the present invention guarantees the goodhomogeneity and stability of the emulsion, and also permits an excellentreconstitution of the final product simply by adding water.

An emulsion is then formed by slowly mixing the aqueous and fattyphases, for example gently incorporating the fatty phase into theaqueous phase, while maintaining constant stirring and, preferably, atemperature of around 4° to 10° C., equally for bacteriological reasons.

An oil-in-water emulsion is thus obtained, with a pH below 5, the exactfigure depending on the composition, but generally between 2.9 and 4.5,containing no egg yolk, and having an albumen/fat ratio of between 0.14and 1.5.

The dry matter content of the said emulsion is preferably between 20 and50% so as to permit pumping, homogenisation and dehydration.

The emulsion is then homogenised, under high pressure, in order toreduce the size of the droplets of the fatty phase to around 1 μm, oreven less.

It has been observed that homogenisation allows the rehydrationqualities of the dehydrated powder to be improved, as well as itsfunctional properties such as, for example, its ability to form a firmand stable gel, which is important in cases where the aim is toreconstitute a product having the appearance, taste and consistency ofmayonnaise.

A two-stage homogenizer may be employed in the usual way. Nevertheless,the precaution may be taken of not going above too high a pressure, ofaround 350 bars, so as to avoid a denaturation of the proteins whichwould cause a loss of functionality and lead to an irreversible phaseseparation of the emulsion.

Homogenisation may be carried out at any temperature well below thecoagulation temperature of egg white, preferably at a temperature of 4°to 40° C., and ideally 4° to 10° C.

The emulsion thus homogenised is then dehydrated by means of any knownprocess, such as freeze drying or atomization.

A powder that may optionally be agglomerated by any known process isthus obtained.

In this way, a powdered product is obtained which can be used directly,after reconstitution by the addition of any food liquid such as water,vinegar, wine, juices of fruits or vegetables, stocks, milk, cream oreven yoghurt for example, or any other substance able to bring aboutrehydration, as a base for salad dressing, mayonnaise or dressing.

The subsequent use made of the reconstituted product depends principallyon the quantity of liquid added to it, and therefore on its viscosity,which determines its consistency, firmer as a base for mayonnaise, moreor less liquid as a base for salad dressing.

Generally, by adding one part by weight of water to 1 to 4 parts byweight of the said product in powder form, it is possible toreconstitute an edible product having the consistency of salad dressingor mayonnaise.

The powdered product according to the invention also has the advantagethat it may be immediately reconstituted cold, in a liquid such aswater, and that it permits the preparation of a homogenous and stableemulsion, without phase separation.

The product obtained following rehydration contains little cholesterol,coming principally from the fat source and possibly from seasonings, andis therefore nutritionally wholesome, whilst having a texture and tastecomparable to salad dressings or mayonnaises produced in a conventionalmanner.

Moreover, the reconstituted product obtained is very stable and can bekept for 2 to 3 days at room temperature and 1 to 2 weeks atrefrigerator temperature, without any phase separation or otherdeterioration, microbiological for example, being observed.

It is possible to add to it, following reconstitution, food ingredientssuch as salts, essential or aromatic vegetable or animal oils, fruit orvegetable juices, spices, creams and yoghurts, or any other condiment inliquid, paste or powder form, or any other flavouring, so as topersonalise the said final product to the taste of the consumer, withoutcausing any destabilisation of the product.

EXAMPLES

The invention is illustrated in greater detail in the following exampleembodiments.

Example 1

A first mixture is prepared comprising 90 kg of pasteurised liquid eggwhite and 3 kg of powdered skimmed milk. This aqueous phase is mixed for20 minutes at 10° C. 8 kg of sunflower oil, previously cooled to 10° C.,is added to this aqueous phase while maintaining constant stirring so asto obtain an oil-in-water emulsion.

The emulsion thus obtained is homogenised so as to obtain a fine stableemulsion with a particle size of 0.35 μm and a dry matter content of22.5%.

The ratio of total proteins to lipids is 1.5 and the ratio of albumen tototal proteins is 0.75.

The said emulsion is dehydrated by atomization in the usual manner.

The powdered product thus obtained has a dry matter content of 97%.

Its composition is as follows: proteins 52%, carbohydrates 10%, lipids34%, mineral salts 1%.

Moreover, 100 g of powdered product contains 7 mg of cholesterol.

The product is reconstituted by adding 75 ml of water to 25 g of productin powder form. A base for salad dressing is obtained, to which may alsobe added vinegar, mustard, salt and spices, or any other seasoning.

The product obtained is comparable, in its texture and taste, to thoseobtained in the traditional manner.

It is also possible to reconstitute the product by adding 150 ml ofwater to 50 g of powder, and then adding 5 g of mustard and 3 g of saltto the reconstituted emulsion and, finally, 300 g of table vegetable oiland 30 g of vinegar.

A mayonnaise having an attractive appearance, a good smell of egg, and asuitable texture and taste is thus obtained.

Example 2

A first mixture is prepared comprising 26 g of mustard, 44 g of vinegar,80 g of lemon juice, 5 g of Worcester sauce and 2 g of salt, which ismixed for about 30 minutes at room temperature. This first mixture isadded to 570 g of pasteurised liquid egg white and 15 g of powderedskimmed milk. This aqueous phase is mixed for 30 minutes at 10° C. Tothis aqueous phase is added 260 g of sunflower oil previously cooled to10° C., while maintaining constant stirring so as to obtain anoil-in-water emulsion, having a pH of around 3.8-4.2.

The emulsion thus obtained is thus homogenized so as to obtain a finestable emulsion with a particle size of less than 6 μm and a dry mattercontent of 36%.

The said emulsion is dehydrated by freeze drying in the usual manner.

The powdered product thus obtained has a dry matter content of 98%.

Its composition is as follows: proteins 20%, carbohydrates 4%, lipids72%, mineral salts 2%.

The ratio of total proteins to lipids is 0.3 and the ratio of albumen tototal proteins is 0.8.

The product is reconstituted by the addition of one part of water to onepart of product. A base for mayonnaise having a pH of 4 is obtained, abase to which may be added sunflower oil, for example, in order toobtain a mayonnaise which is comparable, in terms of texture and taste,to those obtained in the traditional manner.

The base thus prepared remains stable, without phase separation, for atleast 8 hours.

The cholesterol content of the mayonnaise thus obtained is of the orderof 5 mg per 100 g whilst it is at least 180 mg/100 g for a normalmayonnaise prepared by the housewife.

The product may also be reconstituted by adding one part of ketchup toone part of powder. A sauce of the mayonnaise type is thus obtainedwhich is tomato coloured and flavoured, has a pH of 4.5/5.0, and remainsstable for at least 8 hours.

The cholesterol content of the said base is below 5 mg per 100 g ofproduct.

Example 3

A first mixture is prepared comprising 4.8 kg of liquid egg white, 0.17kg of powdered egg white, 0.17 kg of powdered skimmed milk, 0.85 kg ofvinegar and 0.01 kg of sodium chloride.

This aqueous phase is mixed for 30 minutes at 10° C. To this aqueousphase is added 4.0 kg of soya oil previously cooled to 10° C., whilemaintaining constant stirring so as to obtain an oil-in-water emulsionhaving a pH of around 3.8-4.2.

The emulsion thus obtained is homogenized so as to obtain a fine stableemulsion with a particle size below 5 μm and having a dry matter contentof 50%.

The said emulsion is dehydrated by freeze drying in the usual manner.

The powdered product thus obtained has a dry matter content 98%.

Its composition is as follows: proteins 15% carbohydrates 3%, lipids79%, mineral salts 1%.

The ratio of total proteins to lipids is 0.2 and the ratio of albumen tototal proteins is 0.6.

The product is reconstituted by the addition of 2 parts of water to onepart of product. A base for mayonnaise having a pH of 4 is obtained, abase to which may be added sunflower oil, for example, in order toobtain a mayonnaise which is comparable, in terms of texture and taste,to those obtained in the traditional manner.

The base thus prepared remains stable, without phase separation, for atleast 8 hours.

The cholesterol content of the mayonnaise thus obtained is below 5 mgper 100 g of product.

It is also possible to reconstitute the product by adding 3 parts ofwater to one part of powder. A salad dressing is thus obtained, to whichmay be added yoghurt for example, which has a pH of 4.5/5.0, and whichremains stable for at least 8 hours.

The cholesterol content of the said base is around 3 mg per 100 g ofproduct.

Example 4 (Keeping tests)

The powdered product obtained according to Example 2 is packed in 250 mlmetal cans.

These cans are kept for a certain time at room temperature, and a sampleof the product is reconstituted by the addition of water (1 part ofproduct per part of water).

The reconstituted samples are tested by a panel of 15 trained tasters.

The following results are obtained:

for the dry product after 5 months of storage: the product keeps welland is easily rehydrated. The reconstituted product has a taste,appearance and texture comparable to those of a mayonnaise prepared fromthe fresh dried product.

for a product reconstituted from a powdered product stored open for 2months, a slight change in taste is noted.

We claim:
 1. A process for preparing a dehydrated particulate food product comprising:preparing an aqueous mixture by mixing albumen and a food acid; combining and mixing the aqueous mixture with fat in amounts sufficient to obtain an emulsion containing albumen and fat in a ratio of between 0.14:1 and 1.5:1 and having a pH below 5; homogenizing the emulsion; and dehydrating the homogenized emulsion to obtain a dehydrated particulate food product.
 2. A process according to claim 1 wherein the aqueous mixture further comprises vegetable protein and carbohydrate.
 3. A process according to claim 1 wherein the aqueous mixture further comprises milk protein and carbohydrate.
 4. A process according to claim 2 or 3 wherein the aqueous mixture and fat are combined in amounts so that the dehydrated product has a fat content of 30% to 85% by weight, a protein content of 5% to 30% by weight and a carbohydrate content of 1% to 30% by weight.
 5. A process according to claim 4 wherein the aqueous mixture and fat are combined in amounts so that the dehydrated product has a fat content of 65% to 85% by weight.
 6. A process according to claim 4 wherein the aqueous mixture and fat are combined in amounts so that the dehydrated product has a fat content of 30% to 65%.
 7. A dehydrated particulate food product obtained from the process of claim
 4. 8. A process according to claim 1 wherein cholesterol-containing materials incorporated into the emulsion are present in amounts such that the dehydrated product contains less than 10 mg cholesterol per 100 g of dehydrated product.
 9. A dehydrated particulate food product obtained from the process of claim
 1. 10. A dehydrated particulate food product comprising individual dehydrated particles, wherein the individual particles comprise albumen, fat and a food acid, wherein the particles have an albumen-to-fat ratio of between 0.14 and 1.5, and wherein the food acid is present in an amount so that, upon hydration of the particles to prepare an emulsion base product, the emulsion base product has a pH less than
 5. 11. A product according to claim 10 wherein the particles further comprise vegetable protein and carbohydrate.
 12. A product according to claim 10 wherein the particles further comprise milk protein and carbohydrate.
 13. A product according to claim 11 or 12 having a fat content of 30% to 85% by weight, a protein content of 5% to 30% by weight and a carbohydrate content of 1% to 30% by weight.
 14. A product according to claim 13 having a lipid content of 30% to 65% by weight.
 15. A product according to claim 13 having a lipid content of 65% to 85% by weight.
 16. A product according to claim 10 wherein the particles have an average size of 50 microns to 150 microns.
 17. A product according to claim 10 having a cholesterol content of less than 10 mg per 100 g of dehydrated product. 